Toilets for animals that are kept as pets, such as dogs and cats, are known to comprise a box-shaped toilet container and animal litter housed in the toilet container. Known animal litter includes sand, such as bentonite-based sand (see PTL 1 and PTL 2, for example).
Bentonite-based sand swells when it absorbs excreted urine, exhibiting cohesiveness and forming numerous lumps containing sand and urine. Pet owners can easily dispose of the urine by removing the lumps, allowing the animal toilet to be kept in a hygienic state.
Bentonite-based sand is generally produced by adding a sodium source, such as sodium carbonate and water to bentonite fine powder obtained by drying and pulverizing crude bentonite, and mixing these to form a mixture, conveying the mixture to a granulator by a belt conveyor, granulating the mixture with the granulator, and drying the granulated product.